Process For Producing Fermented Milk And Fermented Milk
Provided is a process for producing fermented milk which makes it possible to effectively prevent increases in acidity in the fermented milk during transportation and storage, and also makes it possible to produce fermented milk with a good flavour. Bacteriocin-producing lactic acid bacteria and/or a culture or fermentation product thereof are/is added to a yoghurt mix. The bacteriocin-producing lactic acid bacteria are then killed. Lactic acid bacteria different from the bacteriocin-producing lactic acid bacteria are then added as a starter. It is thus possible to incorporate bacteriocin in yoghurt without directly adding bacteriocin. Since the bacteriocin-producing lactic acid bacteria are killed, intensification of the flavour of cheese, for example, can be prevented, and it is possible to produce fermented milk with a good flavour.
1 . A method for manufacturing fermented milk comprising:
a step of adding bacteriocin-producing lactic acid bacteria and/or cultures or fermentation products of the bacteria to a yoghurt mix;
a step of killing the bacteriocin-producing lactic acid bacteria after the bacteria and/or cultures or fermentation products of the bacteria have been added;
a step of adding a starter to the yoghurt mix containing the bacteriocin-producing lactic acid bacteria which have been killed; and
a step of fermenting the yoghurt mix to which the starter has been added.
2 . The method for manufacturing fermented milk in accordance with claim 1 , further comprising a step of de-oxygen treatment of the yoghurt mix between the step of killing the bacteriocin-producing lactic acid bacteria and the step of fermenting the yoghurt mix.
3 . The method for manufacturing fermented milk in accordance with claim 1 , wherein the acidity in the yoghurt mix to which the bacteriocin-producing lactic acid bacteria are added is pH 6.5-7.5.
4 . The method for manufacturing fermented milk in accordance with claim 1 , wherein the bacteriocin-producing, lactic acid bacteria is in genus Lactococcus.
5 . The method for manufacturing fermented milk in accordance with claim 1 , wherein the bacteriocin-producing lactic acid bacteria is L. lactis or L. cremoris.
6 . The method for manufacturing fermented milk in accordance with claim 1 , wherein the bacteriocin-producing lactic acid bacteria is a lactic acid stock with the deposit number “FERM BP-10966” or “FERM BP-10967” deposited in International Patent Organism Depositary, Advanced Industrial Science and Technology.
7 . The method for manufacturing fermented milk in accordance with claim 1 , wherein the bacteriocin is nisin or lactococcin.
8 . The method for manufacturing fermented milk in accordance with claim 1 , wherein the main component of the starter is L. delbrueckii subsp. bulgaricus or L. helveticus.
9 . The method for manufacturing fermented milk in accordance with claim 1 , wherein the main components of the starter are L. delbrueckii subsp. bulgaricus and Streptococcus thermophilus.
10 . The method for manufacturing fermented milk in accordance with claim 1 , wherein the fermented milk is plain-type yoghurt.
11 . A fermented milk manufactured by the methods described in any one of claims 1 - 10 .